There is a forklift including a hydraulic drive device called an HST (Hydro Static Transmission) mounted between an engine, which is a drive source, and drive wheels. In the HST, a traveling hydraulic pump of a variable displacement type driven by an engine and a hydraulic motor of a variable displacement type driven by operating oil discharged from the traveling hydraulic pump are provided to a main hydraulic circuit that is a closed circuit. The HST allows the vehicle to travel by transmitting driving force of the hydraulic motor to the drive wheels. Patent Literature 1 describes that, in a forklift including an HST, an engine is controlled according to a control accelerator operation amount, which is obtained by limiting an increase rate of an actual accelerator operation amount per hour to a limit value set beforehand.